A Phase 3b, Randomized, Observer-Blind, Placebo-Controlled Multi-Center Study Comparing Immunogenicity, Safety and 1 Year Persistence of Antibodies After Either One or Two Doses of Novartis Meningococcal ACWY Conjugate Vaccine, Administered to Healthy Children 2 to 10 Years of Age.

Study start date: October 7, 2012

Inclusion Criteria: * Healthy children, 2 to 10 years of age who have up to date routine childhood vaccination, according to U.S. ACIP recommendations Exclusion Criteria: 1. Unwilling or unable to give written informed assent or consent to participate in the study. 2. Perceived to be unreliable or unavailable for the duration of the study period. 3. Previous confirmed or suspected disease caused by N. meningitidis. 4. Previously immunized with a meningococcal vaccine (licensed or investigational). 5. Receipt of any investigational or non-registered product within 30 days prior to enrolment or who expect to receive an investigational drug or vaccine prior to the completion of the study. 6. Receipt or plan to receive any vaccines within 30 days before and after administration of each dose of the study vaccine. (certain exceptions influenza vaccines apply) 7. Significant acute infection within the 7 days prior to enrolment or body temperature of 38°C or greater within 3 days prior to enrolment. 8. Previous serious acute, chronic or progressive disease, epilepsy or any progressive neurological disease or history of Guillain-Barre syndrome. 9. History of any anaphylaxis, serious vaccine reactions, or allergy to any vaccine components 10. Impairment/alteration of immune function, either congenital or acquired or resulting from (for example): * receipt of immunosuppressive therapy, * receipt of immunostimulants, * receipt of parenteral immunoglobulin preparation, blood products, and/or plasma derivatives. 11. Known bleeding diathesis, or any condition that may be associated with a prolonged bleeding time.